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The Origin of Species (Barnes & Noble Classics) - Charles Darwin [243]

By Root 1894 0
(sing. FUNGUS). A class of cellular plants, of which Mushrooms, Toadstools, and Moulds, are familiar examples.

FURCULA The forked bone formed by the union of the collarbones in many birds, such as the common Fowl.

GALLINACEOUS BIRDS An order of Birds of which the common Fowl, Turkey, and Pheasant, are well-known examples.

GALLUS The genus of birds which includes the common Fowl.

GANGLION A swelling or knot from which nerves are given off as from a centre.

GANOID FISHES Fishes covered with peculiar enamelled bony scales. Most of them are extinct.

GERMINAL VESICLE A minute vesicle in the eggs of animals, from which development of the embryo proceeds.

GLACIAL PERIOD A period of great cold and of enormous extension of ice upon the surface of the earth. It is believed that glacial periods have occurred repeatedly during the geological history of the earth, but the term is generally applied to the close of the Tertiary epoch, when nearly the whole of Europe was subjected to an arctic climate.

GLAND An organ which secretes or separates some peculiar product from the blood or sap of animals or plants.

GLOTTIS The opening of the windpipe into the oesophagus or gullet.

GNEISS A rock approaching granite in composition, but more or less laminated, and really produced by the alteration of a sedimentary deposit after its consolidation.

GRALLATORES The so-called Wading-birds (Storks, Cranes, Snipes, &c.), which are generally furnished with long legs, bare of feathers above the heel, and have no membranes between the toes.

GRANITE A rock consisting essentially of crystal of felspar and mica in a mass of quartz.

HABITAT The locality in which a plant or animal naturally lives.

HEMIPTERA An order or sub-order of Insects, characterized by the possession of a jointed beak or rostrum, and by having the fore-wings horny in the basal portion and membranous at the extremity, where they cross each other. This group includes the various species of Bugs.

HERMAPHRODITE Possessing the organs of both sexes.

HOMOLOGY That relation between parts which results from their development from corresponding embryonic parts, either in different animals, as in the case of the arm of man, the foreleg of a quadruped, and the wing of a bird; or in the same individual, as in the case of the fore and hind legs in quadrupeds, and the segments or rings and their appendages of which the body of a worm, a centipede, &c., is composed. The latter is called serial homology. The parts which stand in such a relation to each other are said to be homologous, and one such part or organ is called the homologue of the other. In different plants the parts of the flower are homologous, and in general these parts are regarded as homologous with leaves.

HOMOPTERA An order or sub-order of Insects having (like the Hemiptera) a jointed beak, but in which the fore-wings are either wholly membranous or wholly leathery. The Cicadæ, Frog-hoppers, and Aphides, are well-known examples.

HYBRID The offspring of the union of two distinct species.

HYMENOPTERA An order of insects possessing biting jaws and usually four membranous wings in which there are a few veins. Bees and Wasps are familiar examples of this group.

HYPERTROPHIED Excessively developed.

ICHNEUMONIDÆ A family of Hymenopterous insects, the members of which lay their eggs in the bodies or eggs of other insects.

IMAGO The perfect (generally winged) reproductive state of an insect.

INDIGENS The aboriginal animal or vegetable inhabitants of a country or region.

INFLORESCENCE The mode of arrangement of the flowers of plants.

INFUSORIA A class of microscopic Animalcules, so called from their having originally been observed in infusions of vegetable matters. They consist of a gelatinous material enclosed in a delicate membrane, the whole or part of which is furnished with short vibrating hairs (called cilia), by means of which the animalcules swim through the water or convey the minute particles of their food to the orifice of the mouth.

INSECTIVOROUS Feeding on Insects.

INVERTEBRATA, OR INVERTEBRATE ANIMALS Those

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